POSTNATAL MATURATION OF CARDIOVASCULAR REGULATORY SYSTEM

心血管调节功能的生后发育过程 在小于1天-3个月龄的仔猪中研究了机制， 从调节系统的传出流出的观点来看。 因为 心血管和呼吸系统之间的密切关系 控制系统，发展产后调节的各个方面， 后一种制度也正在研究之中。 三个具体目标正在 追踪：1）交感神经活动（均为传出神经）的年龄相关差异 放电和血浆儿茶酚胺水平），2）特征 心脏自主调节的发展（心脏记录） 迷走神经运动神经元和使用HRP技术定位心脏交感神经 神经节后索马），3）呼吸节律的年龄相关变化 发电机（各种强制输入的影响，例如，肺膨胀， 化学感受器刺激）。 录音将从Althesin获得 麻醉或去大脑未麻醉仔猪：传出神经 交感神经活动（内脏、颈交感、肾），传出 膈神经放电，心脏迷走神经纤维，疑核运动神经元 腹外侧疑核、主动脉压、心电图、局部动脉 血流量（尤其是肾脏、肠系膜）和适当标记 脉搏 老年大鼠海马神经元传入放电改变的年龄效应 各种心血管-呼吸受体，例如心肺， 动脉压力感受器，中枢心血管和呼吸系统 将对控制系统进行评估。 交感神经系统中常见的周期性 与心动周期相关的放电和周期性（由EKG指示） 或中枢呼吸循环（由传出膈神经放电指示） 通过互相关和功率谱分析揭示， 特别是功率谱等效性和相干性的测试。 的 脑刺激和应激（如高碳酸血症、缺氧）的影响 还将评估出血。 结果的依赖性将是 在6个年龄组的仔猪中进行了统计学测定。 结果将 有助于我们理解子宫外的循环调节 环境和我们对监管程度的了解， 新生儿的心血管功能。 信息将 这是必要的理解反射参与 对各种应激（高碳酸血症，出血， 缺氧），特别是与生命中最脆弱的时期有关， 那个孩子

The time course of postnatal development of cardiovascular regulatory mechanisms is being studied in piglets Less than 1 day-3 months of age, from the viewpoint of efferent out-flow of the regulatory system. Because of the close interrelationship between the cardiovascular and respiratory controlling systems, aspects of developing postnatal regulation of the latter system are also being studied. Three specific aims are being pursued: 1) age-related differences in sympathetic activity (both efferent discharge and plasma catecholamine levels), 2) characteristics of development of autonomic regulation of the heart (recordings from cardiac vagal motoneurons and use of HRP techniques to locate cardiac sympathetic postganglionic soma), 3) age-related changes in the respiratory rhythm generator (efects of various forcing inputs, e.g., lung inflation, chemoreceptor stimulation). Recordings will be obtained from Althesin anesthetized or decerebrate unanesthetized piglets of: efferent sympathetic activity (splanchnic, cervical sympathetic, renal), efferent phrenic discharge, cardiac vagal fibers, motoneurons in nucleurs ambiguus and ventrolateral nucleus ambiguus, aortic pressure, EKG, regional arterial blood flow (particularly renal, mesenteric) and appropriate marking pulses. The age-related effects of alterations in afferent discharge from various cardiovascular-respiratory receptors, e.g. cardiopulmonary, arterial baroreceptors, on central cardiovascular and respiratory controlling systems will be evaluated. Common periodicities in sympathetic discharge and periodicities related to the cardiac cycle (indicated by EKG) or central respiratory cycle (indicated by efferent phrenic discharge) are being revealed by cross correlation and power spectral analyses, particularly tests for power spectral equivalence and coherence. The effects of brain stimulation and of stresses such as hypercapnia, hypoxia and hemorrhage will also be evaluated. Age-dependency of results will be determined statistically in 6 age groups of piglets. The results will contribute to our understanding of circulatory adjustments to extrauterine environment and to our knowledge of the degree of regulation of cardiovascular function available in the neonate. Information will be obtained which is necessary for the understanding of reflexes involved in physiological adjustments to various stresses (hypercapnia, hemorrhage, hypoxia), relevant especially to the most vulnerable period in the life of the child.